Answer: 1) 2, 3, 4, 9, 32, 279, 8896, 2481705, 22077238784
2) 2,490,924
3) Neither
Step-by-step explanation:
[tex]S_n=S_{n-2}\cdot (S_{n-1}-1)\quad \\\\S_1=2\quad given\\S_2=3\quad given\\S_3=S_1(S_2-1)\quad =2(3-1)\quad =4\\S_4=S_2(S_3-1)\quad =3(4-1)\quad =9\\S_5=S_3(S_4-1)\quad =4(9-1)\quad =32\\S_6=S_4(S_5-1)\quad =9(32-1)\quad =279\\S_7=S_5(S_6-1)\quad =32(279-1)\quad =8,896\\S_8=S_6(S_7-1)\quad =279(8896-1)\quad =2,481,705\\S_9=S_7(S_8-1)\quad =8896(2481705-1)\quad =22,077,238,784[/tex]
[tex]\sum^8_{k=1}S_k\\\\=S_1+S_2+S_3+S_4+S_5+S_6+S_7+S_8\\\\= 2,490,924\\[/tex]
Neither
Not arithmetic because the difference between each of the terms is not the same.
S₂ - S₁ S₃ - S₂ S₄ - S₃
3 - 2 = 1 4 - 3 = 1 9 - 4 = 5
Not geometric because the ratios between each of the terms is not the same.
[tex]\dfrac{S_2}{S_1}=\dfrac{S_3}{S_2}\qquad \rightarrow \dfrac{3}{2}=\dfrac{4}{3}\qquad \rightarrow \text{cross multiply to get}: 9\neq 8[/tex]
